1170 fuel system fixed but tranny went BANG

[Ron Sa]

I took your advice and took the primer pump apart. Sure enough there was crud in the primer pump restricting the flow. As also suggested, I also found an aftermarket plunger asm. Engine is running good again but the saga continues. Have a cup of coffee and put a log on the fire----or go help mama cook the turkey. LOL


Typically when the engine is not completely warmed up, I pick a lower gear and work part throttle for a few minutes so I plowed about a half mile in 3rd. They it slipped out of 3rd gear with a LOUD BANG. There were no additional bad sounds. All was quiet except the engine racing but the loud bang was one of those no more plowing this year noises.


I looked at the shift lever and it was still in 3rd position. That seemed strange for slipping out of 3rd. I moved the lever back to neutral and then back into 3rd. 3rd gear had become totally disconnected from the lever in the cab. I pulled the lever back into 4th which felt normal and the tractor would move. I eased back to the barn in 4th without any proverbial monkey wrench in the gears noises or clunking.

Back in the barn, I easily moved the shift lever out of 4th back to neutral but letting the clutch partially out inched the tractor forward. Putting the lever in 3rd position, the tractor would now also inch forward. That seemed strange.


1st, 2nd, and reverse shifted normal except the transmission was locked when put in each of those three gear positions. After a little head scratching, I figured that the transmission must have stayed in 4th and was probably locking in two gears.

YUP the shift lever was totally disconnected and freely moved completely in the 3rd 4th slot.


Here are pictures of the mechanism that I think probably contains the malfunction. The shifter fork contains a square cornered locking detent for each gear. I haven't opened the inspection hole yet but I am suspecting that the shifter fork is split and the locking detent may be still locked.

My repair manual shows the power shift has similar range shift hardware. Have any of you had this same problem with the 70 series?


I am puzzled why 3rd gear under load might apply a breaking force against the shifter fork. I suspect the first owner may have pulled a bigger plow and ran a lot of hours in 3rd for much of its first 2500 hours. The gear might be worn. I havent had much need to use 3rd a lot. The fix will likely be time consuming. I know the cab has to come off in order to remove the top cover.

I have gotten too old. The junkman should be held at bay. A lot of the tractor is still good.

Happy Thanksgiving Day.

 

[mEl]

The cab does not have to come off, I have removed many without. Every early powershift tractor required top cover for removal of the powershift assembly and I have done more than I can guess. If you remove all the top cover bolts you can pick the cover up and fold the shift levers up in the cap and take it out over the RH side. I have never had to but you could take the right rear cab mount loose from the axle and jack the cab up a couple inches, The center rear cap bolt will not come out because of the DOM spool but the cap can be removed with it in place in the cap. It's not really that bad a job. An hour or two you will be looking at the shifter assembly. Be sure to power wash and use a blow gun to clean the area before lifting the cover. there will be a lot of years accumulation of dirt under the floor board, you do not want that going through your hydraulic pump., Ron, I always used a long 3/8 bolt bent 90 degrees screwed into a hole in the top cover so a helper can take weight while you position the shifters. HTH. Mel

This post was edited by mEl on 11/25/2021 at 07:09 am.

 

[Ron Sa]

mEI Thanks for the information. I have a nice step stool for getting in and out of the back of my pickup that will probably allow this old man to stand and lean in thru the door and remove the inspection plate. I left my small lighted mirror between the seats of a car that I recently sold. bummer!! Need to order another one to do the inspection with. I can probably reach far ehough to remove all the top cover bolts. Last winter, I jury-rigged my cherry picker to remove and reinstall the seat. The top cover should be easier to hook and maneuver out either thru the door or thru the side window if necessary.

I cleaned a lot of the crud from the top cover a year ago when I split the tractor to fix the clutch. The back half of the cover probably still has 49 years of crud. My bill of sale says I bought the 1170 on this day 11/25/79.

It has served me well for 42 years but I only put 2600 hours on it because I only farm 105 acres. 84 acres tillable.

 

[Ron Sa]

PS to mEI

My IT service manual tells me the platform had to be removed. Thanks again very much for the correction. That make the decision whether to tackle the job or not much easier. Am I correct in thinking the block held on by four bolts will allow the entire fork assembly to be removed? other than the high low shifter.

 

[mEl]

The dual range shaft interlocks so the shifter can be removed easily. The cap will come out sidedways under the cab floor, just raise it, move it ahead far enough to fold the shift levers up into the cap and turn the cap and take it out, you will need a hand I am sure but it is not hard.

This post was edited by mEl on 11/25/2021 at 02:47 pm.

 

[Ron Sa]

mEI Thanks for the info.

About how much does the cap (top cover) weigh?

 

[mEl]

(quoted from post at 12:43:17 11/26/21) mEI Thanks for the info.

About how much does the cap (top cover) weigh?

robably 50-75 lbs. you surely can get some young help.